1. Technical Field
This application relates to a surgical apparatus and more particularly to a surgical biopsy apparatus for resecting and removing tissue through the apparatus.
2. Background of Related Art
Biopsy is the excision of a small section of tissue from a patient for diagnosis of malignancy or other diseases. For cancerous tissue and many other types of diseases, early diagnosis and tissue removal is critical since early detection increases the chances of successful treatment and survival.
Numerous devices are currently available for performing biopsies of tissue, such as breast tissue or liver tissue. These devices function to dissect a portion of the tissue and remove it from the body for pathology to determine whether the tissue is malignant.
The most invasive procedure is referred to as open excisional biopsy. In this procedure, large tissue samples are surgically removed through a large incision, requiring long patient recovery times, risking disfigurement, e.g. of the breast in breast biopsy, and resulting in increased pain, scarring and morbidity.
In an attempt to overcome the disadvantages of open surgery, more minimally invasive instruments have been developed. One minimally invasive approach utilizes a percutaneous instrument referred to as a fine needle biopsy instrument. In this instrument, a needle and syringe are inserted directly through the tissue, into the target tissue, e.g. the lump, to remove sample cells for pathology. For a breast biopsy, the instrument is inserted directly into the breast; for liver biopsy the instrument is inserted directly through the abdomen. One disadvantage of this technique is that numerous cell samples are required to be taken from the tissue to obtain a sufficient mass for testing, thereby requiring numerous needle sticks, increasing the time required for the procedure, and possible requiring re-localization by imaging of the lesion. Another disadvantage is that careful locational tracking of the tissue cells, which is required for accurate analysis, can be compromised. Also, with these devices there is a greater potential for false negatives due to the small sized specimens being removed without removal of sufficient surrounding areas of healthy tissue for comparison. Hemostasis during a biopsy is also an issue.
Another type of minimally invasive device is referred to as core needle biopsy. This device has a spring actuated cutter and removes a larger specimen than the fine needle biopsy instruments. The specimen is suctioned into a side window in the needle and then back through the proximal end of the needle. Although larger than fine needle biopsy instruments, these needles are still relatively small, e.g. 2 mm in diameter. Since typically removal of between five and twenty tissue cores of 2 mm in diameter and 20 mm in length is required for accurate pathology, five to twenty needle sticks into the patient of this 2 mm diameter needle is required. These devices also have the disadvantage that the spring force cutting action may displace malignant cells into the adjacent normal tissue or into the track along the path of entry. Thus, as the needle comes out, cancerous tissue can potentially be withdrawn. Also, the amount of false negatives can be high because of inadequate removal of surrounding healthy tissue. Like fine needle biopsy, success and accuracy of the procedure is skill dependent because the device must be maneuvered to various positions and these different positions accurately tracked.
Some percutaneous devices enable multiple specimens to be removed with a single needle stick. The specimens are removed from the proximal end of the needle by a vacuum. However, the device has a window formed in the sidewall to receive the tissue for resection by a cutter. Since only the tissue received within this lateral window is cut, the amount of tissue that can be removed and cut is limited. Therefore, the device must be rotated and maneuvered so different tissue sections can enter the window and be resected. This manipulation is not only time consuming and skill dependent, but detracts from the accuracy of tracking the tissue, thereby reducing the diagnostic accuracy.
To remove larger specimens of tissue utilizing this lateral window approach, the device would have to be made significantly larger. However, if made too large, then the procedure becomes more invasive and starts to resemble an open surgical procedure with the attendant disadvantages enumerated above. The larger instrument can cause additional bleeding because of the large incision and requires closure of a larger incision, thereby increasing scarring, lengthening patient recovery time, and adding to the cost, time and complexity of the procedure. Additionally, if the needle is too large than a large amount of tissue will be removed in the path from the skin surface entry point to the interior of the target tissue where the lesion is located. If pathology indicates the lesion is benign, then a large tissue mass would have been unnecessarily removed, resulting in more pain, a larger scar, and possible disfigurement. The disfigurement issue is more pronounced with procedures such as breast biopsy.
It would therefore be advantageous to provide a surgical biopsy device which is easy to use, reduces surgical procedure time, reduces bleeding and can minimally invasively remove large tissue samples sufficiently intact to improve the accuracy of pathology.
The present invention overcomes the disadvantages and deficiencies of the prior art by providing a surgical apparatus for removing a portion of tissue comprising an elongated body having a distal edge, a collapsible cutting member mounted to the elongated body, having an opening therethrough, and extending distally of the distal edge of the elongated body. The cutting member has a closed loop conductive surface and is movable from a first loop configuration to a second smaller loop configuration. An exposed conductive distal edge of the cutting member forms an electrosurgical cutting surface for applying electrical energy to tissue. The cutting member resects a tubular region of tissue as the apparatus is advanced through tissue and the resected tissue extends through an opening in the cutting member for containment within the elongated body. The cutting member is movable to the second loop configuration to further sever the tissue.
The elongated body is preferably flexible and preferably comprises an inner tube and an outer tube wherein the cut tissue is stored in an interior lumen of the inner tube. The cutting member is preferably electrically connected to an RF generator to apply RF energy to the tissue.
In one embodiment, the elongated body of the apparatus is dimensioned for insertion through a working channel of an endoscope. In other embodiments, the elongated body is inserted laparascopically through a trocar, intraluminally through a catheter, or directly through the skin (percutaneously).
An obturator can be positioned within the elongated body which is extendable distally from the elongated body past the distal edge of the cutting member to penetrate tissue. The obturator is preferably spring biased to a protected retracted position such that a sharp tip of the obturator is positioned proximally of the distal edge of the cutting member.
The present invention also provides a surgical tissue biopsy system comprising an endoscope having a channel formed therein for receiving a surgical instrument, and a tissue biopsy apparatus insertable through the channel of the endoscope. The biopsy apparatus is connectable to a generator for supplying RF energy and has a collapsible cutting member mounted at a distal end thereof. The cutting member has a distally exposed conductive cutting surface for cutting tissue as the apparatus is advanced and the cutting member is energized to apply radiofrequency energy to the tissue. The cutting member is collapsible to a smaller configuration to farther sever tissue.
The cutting member preferably forms a substantially circular loop having a distal edge protruding from an elongated body member of the apparatus.
The present invention also provides a method of taking a tissue biopsy comprising:
providing an apparatus having an elongated member and a collapsible cutting member forming a cutting loop with a distally exposed conductive cutting surface fixedly mounted to the elongated member and extending past the elongated member;
introducing the apparatus into the body;
applying radiofrequency energy to the cutting member in a first loop configuration;
advancing the apparatus so the exposed surface contacts and severs the target tissue and enables the severed tissue to be captured within the interior of the elongated member; and
collapsing the cutting member to a second smaller loop configuration.
The step of collapsing the cutting member preferably comprises pulling the member proximally to reduce the size of the cutting loop.
In one embodiment, the method further comprises the step of inserting the apparatus through a working channel in an endoscope. In this embodiment, the apparatus can be introduced transjugularly or transanally into the body. In another embodiment, the step of introducing the apparatus into the body comprises the step of introducing the apparatus percutaneously into the body.
The method of introducing the apparatus into the body may also include the step of distally advancing an obturator to penetrate tissue. The method may also further comprise the step of removing the tissue from the interior of the elongated member after the procedure by advancing the obturator within the elongated member to eject the tissue.
In one embodiment, the step of introducing the apparatus into the body comprises the step of introducing the apparatus into breast tissue for severing and removing a lesion in the breast. In another embodiment, the step of introducing the apparatus comprises the step of advancing the apparatus through the esophagus and stomach wall into the liver or kidney.